Many accidents and diseases result in loss of a limb through amputations. Many of these amputations are for limbs of the lower extremities of the body. In an effort to improve the life of the person undergoing an amputation, significant research has been undertaken in developing artificial limbs that function like human limbs. These artificial limbs are often referred to as prosthetic devices, or prosthesis. Most prosthetic devices have a socket that attaches the prosthetic device to a residual limb of the amputee. Once it is attached, in order for the prosthetic device to function properly and comfortably the prosthetic device needs to be aligned properly relative to the user's body. Thus, alignment of a prosthesis is an important element of optimizing its function.
In common clinical practice, prosthetic alignment techniques primarily consist of three steps: bench alignment, static alignment and dynamic alignment. Bench alignment is generally done on a table without the user and may include attaching the socket to the rest of a prosthetic device at the proper location. Static alignment is normally performed in a standing position while the patient is placing weight on the prosthesis. The aim of static alignment is to make necessary corrections in height, inclination and translation to adjust the prosthesis to the specific biomechanical profile of the user before they take their first step with the device. Dynamic alignment is often done while the user is walking. For example, the prosthetist observes the amputee's walking quality and finetunes the prosthetic alignment to improve gait deviations. This step is repeated until both the amputee and the prosthetist determine that clinically acceptable alignment is achieved.
Most of these alignment steps are performed by visual estimation and take a long time to perform. As a result, prosthesis alignment has been an imprecise and inconsistent practice based primarily on subjective input from the amputee and the person performing the alignment. Because alignment relies primarily on the opinion of the technician performing the operation, it also generally requires a high level of expertise and experience and can thus become costly.
Therefore, a need exists for providing an improved method and system of facilitating alignment of a prosthetic device.